Need help with this one piece! (Floral ornment)
You could do it:

Manually. It will garantee that you're very close to the real object and you'll be able to make some close-up shots. Here is just a try with a small detail, you'll need to do if with whole shape of course:




With a Project From View texture: Draw the contours of the whole shape, extrude up, bevel, shade smooth, give it a Subdivision Surface modifier, unwrap from the top orthogonal view with the Project from View option, give it a material with the original photo as Image Texture, you can even add a bit of bump:







You can even cut with the knife or inset to extrude up or down some parts:



With curves: Draw some curves that roughly follow the ornments, bevel them, use the Profile tool, scale the vertices with AltS if you want more thickness, and when you're glad, convert to mesh: